Voltage regulators are switch mode power supplies employed for regulating and controlling a core voltage supply in an on-chip digital logic circuit such as, for example, a microcontroller, a microprocessor, and a microcomputer. Most on-chip digital circuits are configured to use two power supplies, which includes an on-chip regulator and an off-chip regulator. At a given time, only one regulator will be used. So in the case where an off-chip regulator is acting as a supply for on-chip digital logic, the on-chip regulator needs to be powered down. The power down control for the on-chip regulator cannot be on core supply as initially core supply itself is not there and also there is no way to know which regulator is generating core supply. The solution presented detects whether the off-chip inductor is connected to the on-chip regulator and if not, enters power down state.
Most prior art voltage regulators employ an input/output (I/O) pin for performing the power down operation of the on-chip regulator when the off-chip regulator is supplying the core supply voltage. The use of input/output (I/O) pin adds to the cost.
Based on the foregoing, it is believed that a need exist for an improved peak current controlled switching voltage regulator system and method for providing a self-power down mode, as described in greater detail herein.